New research suggests that there may be some genetic basis for the origin of sexual orientation. Scientists have found that almost a quarter of women who have more than one gay son processed X chromosomes in the same way, as opposed to other women whose chromosomes are randomly processed in their bodies.
The research conducted at the University of California, confirms, according to the study’s co-author Sven Bocklandt, “that there is a strong genetic basis for sexual orientation, and that for some gay men, genes on the X chromosome are involved.”
The study was undertaken among 97 mothers of gay sons and 103 mothers who did not have gay sons, and is published in the February issue of the journal Human Genetics. Forty-four of the women had more than one gay son.
The phenomenon of being more likely to inactivate one X chromosome, known as “extreme skewing”, is apparently usually only found in families that have major genetic irregularities. While the scientists aren’t exactly sure as to what all this means, they believe that it does indicate some kind of link between sexuality and genetics.
There has been an ongoing, often fiery, debate on the issue, with many religious fundamentalists convinced that sexuality is a choice and not a biologically determined behaviour. Gay activists on the other hand are concerned that if a single or dominant genetic origin of sexuality is found, that this may lead to genetic tinkering to remove a child’s homosexuality.
The study doesn’t explain why the chromosome phenomenon is not a factor among the other mothers of gay sons, and especially the mothers of only one gay son. Some critics have also pointed out that the study focussed on a small group of woman and needs to be replicated to be verified.